KR102543767B1 - Light emitting diode for night vision imaging system - Google Patents

Abstract

Disclosed is a light emitting diode for a night vision lighting system of the present invention. The present invention provides a package body that is a black body, a light emitting chip seated on an opening area of the package body, and coupled to the package body, at least some of the wavelengths of light emitted from the light emitting chip. It includes a filter unit that blocks or reduces.

Description

Light emitting diode for night vision lighting system {LIGHT EMITTING DIODE FOR NIGHT VISION IMAGING SYSTEM}

Embodiments of the present invention relate to devices, and more particularly, to light emitting diodes for night vision lighting systems.

Avionics, a compound word of Aviation and Electronic, corresponds to the brain, nerves, and five senses of an aircraft. It is an integration of related onboard electronic equipment and various sensors. It processes and processes data received from various sensors. It means a system that provides the function to be displayed. Recently, when avionics lighting and display devices are used for military purposes, a function compatible with a Night Vision Imaging System (NVIS) is required.

The night vision system has been introduced into aircraft weapon systems since the 1990s to perform special operations at night and maximize pilots' missions. It is used for night operations. The night vision system allows the pilot to perform operations and missions similar to daytime by recognizing the external situation by wearing night vision goggles used in the form of glasses even when lighting is not supported at night. Night vision goggles are a device that enables the identification of external images of weak brightness that cannot be recognized by the naked eye through an image intensifier tube. It has been developed to have the best relative response, and the aircraft's interior/exterior lighting system must maintain the light in the near-infrared region of the night vision goggles detection wavelength band to a detectable minimum level for smooth operation of the night vision goggles. And the night vision system Class A and the night vision system Class B are classifications of aircraft interior lighting devices. It refers to a night vision lighting system having spectral response characteristics by adding a blue cut-off filter to an objective lens. Night vision system Class A is mainly used for rotary-wing aircraft and night vision system Class B is mainly used for fixed-wing aircraft. allow the use of And in the case of radiance of the night vision system, Class B devices must satisfy all requirements of Class A devices.

Recently, compared to existing light sources such as incandescent lamps, halogen lamps, and xenon lamps, high-efficiency white LEDs, which are lightweight, compact, and consume less energy, are being actively used as light sources for avionics. However, in order to apply a white LED to a light emitting diode for a night vision lighting system in the field of avionics, the light in the near-infrared region inevitably emitted from the white LED must be blocked as much as possible so as not to impair the sensitivity of the night vision lighting system.

Embodiments of the present invention provide a light emitting diode for a night vision lighting system.

An embodiment of the present invention is a package body that is a black body, a light emitting chip seated on an opening area of the package body, coupled to the package body, and at least one of wavelengths of light emitted from the light emitting chip. Disclosed is a light emitting diode for a night vision lighting system including a filter unit for blocking or reducing some wavelengths.

In this embodiment, the light emitting chip may be a blue chip.

In this embodiment, a packing part disposed in the opening area of the package body and including a yellow phosphor for conversion to white may be further included.

In this embodiment, the package body may include a package body base having the opening area and a protrusion protruding from the package body base and disposed to surround an edge of the filter unit.

In this embodiment, the filter unit may include a dye layer disposed to face the light emitting chip and containing a dye, and a protective layer disposed on the dye layer.

In this embodiment, the protective layer may include a polyethylene terephthalate (PET) film.

In this embodiment, the dye layer may include a silicone-based or acrylic resin into which the dye is mixed.

In this embodiment, the chromaticity of the light emitting diode for the night vision lighting system may be adjusted by varying at least one of a thickness of the filter unit, a color temperature of light emitted from the light emitting chip, and a dye concentration of the filter unit.

Other aspects, features and advantages other than those described above will become apparent from the following drawings, claims and detailed description of the invention.

These general and specific aspects may be practiced using a system, method, computer program, or any combination of systems, methods, or computer programs.

The light emitting diode for a night vision lighting system according to embodiments of the present invention can provide light suitable for a night vision lighting system through a simple structure.

Light emitting diodes for a night vision lighting system according to embodiments of the present invention can prevent light emitted from a light emitting chip from being emitted to the outside without passing through a filter unit.

The light emitting diode for a night vision lighting system according to embodiments of the present invention provides light with a high recognition rate in a night vision lighting system, and can block or reduce light that lowers the recognition rate.

1 is a cross-sectional view showing a light emitting diode for a night vision lighting system according to an embodiment of the present invention.
FIG. 2 is a graph showing the intensity of light according to the wavelength of the light emitting diode for a night vision lighting system shown in FIG. 1 and a comparative example.
3 is a graph showing a change in transmittance according to a dye concentration in a filter unit of a light emitting diode for a night vision lighting system.
FIG. 4 is a graph showing changes in chromaticity coordinates of the light emitting diode for the night vision lighting system according to the dye concentration of the filter unit of the light emitting diode for the night vision lighting system shown in FIG. 1 .
FIG. 5 is a graph showing radiant luminance of the night vision lighting system according to the dye concentration of the filter unit of the light emitting diode for the night vision lighting system shown in FIG. 1 .
6 is a cross-sectional view showing a light emitting diode for a night vision lighting system according to another embodiment of the present invention.

Since the present invention can apply various transformations and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. Effects and features of the present invention, and methods for achieving them will become clear with reference to the embodiments described later in detail together with the drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and when describing with reference to the drawings, the same or corresponding components are assigned the same reference numerals, and overlapping descriptions thereof will be omitted. .

In the following embodiments, terms such as first and second are used for the purpose of distinguishing one component from another component without limiting meaning.

In the following examples, expressions in the singular number include plural expressions unless the context clearly dictates otherwise.

In the following embodiments, terms such as include or have mean that features or components described in the specification exist, and do not preclude the possibility that one or more other features or components may be added.

In the following embodiments, when a part such as a film, region, component, etc. is said to be on or on another part, not only when it is directly above the other part, but also when another film, region, component, etc. is interposed therebetween. Including if there is

In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, since the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, the present invention is not necessarily limited to the illustrated bar.

In the following embodiments, the x-axis, y-axis, and z-axis are not limited to the three axes of the Cartesian coordinate system, and may be interpreted in a broad sense including these. For example, the x-axis, y-axis, and z-axis may be orthogonal to each other, but may refer to different directions that are not orthogonal to each other.

When an embodiment is otherwise implementable, a specific process sequence may be performed differently from the described sequence. For example, two processes described in succession may be performed substantially simultaneously, or may be performed in an order reverse to the order described.

1 is a cross-sectional view showing a light emitting diode for a night vision lighting system according to an embodiment of the present invention.

Referring to FIG. 1 , a light emitting diode 100 for a night vision lighting system may include a package body 110, a light emitting chip 120, a packing part 130, and a filter part 140.

An opening 110a may be disposed in the package body 110 . A side surface of the opening 110a may be formed to be inclined. In addition, the package body 110 may be formed as a black body. Such a black body may be manufactured by mixing black dye with resin or by coating the outer surface of a certain member with a black material. As another embodiment, the black body may be manufactured by processing a black material. At this time, although not shown in the drawing, a terminal may be inserted into the package body 110 to be connected to the light emitting chip 120 . In this case, the terminal protrudes to various surfaces such as the bottom or side surface of the package body 110 and can be connected to external electronic devices.

The light emitting chip 120 may emit light of various colors. For example, the light emitting chip 120 may emit blue light. In this case, the light emitting chip 120 may include a GaN-based blue chip.

The packing part 130 may be disposed inside the opening 110a of the package body 110 . At this time, the packing unit 130 may block the light emitting chip 120 from the outside. In this case, the packing unit 130 may include YAG (Yttrium Aluminum Garnet), which is a yellow phosphor, and may include a silicone-based or acrylic resin including such a yellow phosphor.

Light emitted from the light emitting chip 120 as described above may emit white light due to a yellow phosphor. In this case, the color temperature reaching the filter unit 140 through the packing unit 130 can be adjusted by adjusting the concentration of the yellow phosphor. Specifically, this color temperature may be about 6500-7500K.

The filter unit 140 may include a dye layer 141 and a protective layer 142 . The dye layer 141 may be manufactured by mixing a night vision imaging system (NVIS) Green A dye with a silicone-based or acrylic resin. In this case, the wavelength of light blocked from light passing through the filter unit 140 and the intensity of light passing through may vary according to the concentration of the dye. These dyes may be mixed in a silicone-based or acrylic resin in a weight ratio, and may be stirred using a co-rotational stirrer to improve dispersibility within the silicone-based or acrylic resin. In addition, a curing agent may be mixed and stirred again.

The filter unit 140 as described above may block light having a wavelength within a range of approximately 600 nm or more and 900 nm or less. That is, when the light emitted from the light source 120 passes through the packing unit 130 and passes through the filter unit 140, the filter unit 140 transmits light having a wavelength within a range of 600 nm or more and 900 nm or less. Some may not pass through or may be completely blocked. Light having a wavelength within a range of 600 nm or more and 900 nm or less as described above may be a wavelength range that affects the sensitivity of the night vision lighting system. That is, when light having a wavelength within a range of 600 nm or more and 900 nm or less is incident to the night vision lighting system, readability of the night vision lighting system may be impaired. Therefore, it is possible for the filter unit 140 to effectively block these wavelengths.

A protective layer 142 may be disposed on the dye layer 141 . In this case, the protective layer 142 may include a polyethylene terephthalate (PET) film. The dye layer 141 as described above may be coated on the protective layer 142 through a knife coater and then cured at 80° C. for 1 hour to be disposed on the protective layer 142 .

The light emitting diode 100 for the night vision lighting system as described above may be used when the night vision lighting system is used. In this case, light emitted from the light emitting chip 120 may pass through the filter unit 140 through the packing unit 130 and be transmitted to the night vision lighting system. In this case, in the night vision system, only a part of the light emitted from the light emitting diode 100 for the night vision system is transmitted, so that it is possible to easily recognize the light emitted from the light emitting diode 100 for the night vision lighting system even at night.

In the above case, the light emitted from the light emitting diode 100 for the night vision system is blocked by the package body 110, which is a black body, so that it can be emitted only to the upper side of the opening region 110a. In particular, when the package body 110 is not a black body, light emitted from the light emitting chip 120 passes through the package body 110 and is emitted to the outside, thereby increasing the recognition rate of light emitted from the light emitting chip 120 in the night vision lighting system. Not only can it reduce, but it can also hinder awareness. However, the above problems can be solved by forming the package body 110 as a black body as described above.

In relation to the experimental results below, the white light emitting diode may refer to a case in which the package body 110 is formed of a transparent material, and may refer to a case in which the filter unit 140 is not provided.

FIG. 2 is a graph showing the intensity of light according to the wavelength of the light emitting diode for a night vision lighting system shown in FIG. 1 and a comparative example.

Referring to FIG. 2 , in order to check the shielding effect in the near-infrared region of the light emitting diode (100, color temperature 6500-7500 K) for the night vision system manufactured by the package body 110 which is a black body, the night vision light system of the white body package body 2 shows an emission spectrum evaluated by comparison with a conventional light emitting diode (comparative example). For an accurate comparative evaluation, when manufacturing light emitting diodes for each night vision system, the color of the package body is different from black and white, but a blue chip with the same wavelength and luminous intensity is mounted on the package body with the same external structure and dimensions, and the yellow phosphor concentration is also made to match the same

Referring to FIG. 2, the intensity of light radiated from the light emitting diode for the night vision system made of the black body package body is reduced by 28% at 450 nm, 77% at 550 nm, and 78% at 650 nm, respectively, compared to the white body package body. can know In addition, compared to light emitting diodes for night vision lighting systems of a white body package body, light that inhibits the sensitivity of the night vision system (NVIS) is radiated in the near-infrared region of 650 nm or more rather than the blue region of 450 nm in a relatively black body light emitting diode for night vision lighting system. It can be seen that it is reduced and released. In addition, as a result of visual inspection in a dark room, it can be confirmed that the light emitted from the light emitting diode for the night vision lighting system is significantly reduced in the light emitting diode for the night vision lighting system manufactured with the black body package body. Therefore, based on this result, when using the black body package body, it is possible to effectively and easily manufacture a light emitting diode for a night vision lighting system.

FIG. 3 is a graph showing a change in transmittance according to a dye concentration of a filter unit of a light emitting diode for a night vision lighting system shown in FIG. 1 .

Referring to FIG. 4 , transmittance (transmission spectrum) of light emitted from the light emitting chip 120 may be different according to the temperature of the dye of the dye layer 141 . Specifically, the transmittance of the acrylic film containing no dye in the dye layer 141 shows excellent optical characteristics of 82% or more in the vicinity of 400 nm and 86% or more in the vicinity of 520 nm. At this time, as the concentration of the dye in the dye layer 141 increases, the transmission region rapidly decreases in the visible light region, and the transmittance peak observed between 510 and 520 nm also rapidly decreases. In addition, when the concentration of the dye is 1 wt% or more, the transmittance between 600 and 900 nm that affects the sensitivity of the night vision system (NVIS) is rapidly reduced to less than 1%. The filter unit 140 maximizes the night vision performance by minimizing the radiant luminance and considers night-time readability so that the inside information of the cockpit can be identified with the naked eye, and external lighting and information are identified using the night vision goggles It should be possible. Therefore, when considering the transmittance in the visible ray region, the optimal dye concentration may be around 1 wt%.

The above result may be different depending on the thickness of the dye layer 141 when the concentration of the dye is constant. Specifically, when the concentration of the dye is 1 wt %, the relationship between the thickness and transmittance of the dye layer 141 may be the same as the relationship between the concentration of the dye and transmittance of the dye layer 141 .

FIG. 4 is a graph showing changes in chromaticity coordinates of the light emitting diode for the night vision lighting system according to the dye concentration of the filter unit of the light emitting diode for the night vision lighting system shown in FIG. 1 .

Referring to FIG. 4, FIG. 6 shows a change in 1976 UCS chromaticity coordinates according to a change in dye concentration.

과

은 측정된 시료의 1976 UCS(Unform Chromaticity scale System) 색도 좌표이며,

과

은 지정된 색영역에서 1976 UCS 색도 좌표에서 중심점을 나타낸다. MIL-STD-3009 규격에 규정된 NVIS Green A의 중심좌표와 반경은 도 4에 나타낸 것처럼 각각

이다. 도 4를 보면 색도 좌표는 염료의 농도에 비례적으로 변화하는 것을 알 수 있으며, 염료의 농도가 3 wt%에서 포화(Saturation)되는 것을 확인할 수 있다. 염료의 농도와 염료층(141)의 두께 조절 뿐만 아니라 발광칩(120)의 색도 조절을 통해 최적화를 하는 경우 쉽게 MIL-STD-3009에서 규정하는 Green A색도를 만족시킬 수 있다.In [Equation 1]

class

is the 1976 UCS (Unform Chromaticity scale System) chromaticity coordinates of the measured sample,

class

represents the center point in 1976 UCS chromaticity coordinates in the specified color gamut. The center coordinates and radius of NVIS Green A specified in the MIL-STD-3009 standard are respectively as shown in FIG.

am. 4, it can be seen that the chromaticity coordinates change proportionally to the concentration of the dye, and it can be seen that the concentration of the dye is saturated at 3 wt%. In the case of optimizing not only the concentration of the dye and the thickness of the dye layer 141, but also the chromaticity of the light emitting chip 120, it is possible to easily satisfy the Green A chromaticity specified in MIL-STD-3009.

That is, based on FIG. 4 , the thickness of the dye has the same directionality and tendency as the concentration of the dye. In addition, when adjusting the chromaticity of the light emitting chip 120, it may move to the right or left of the graph shown in FIG. For example, when the chromaticity of the light emitting chip 120 is greater than the chromaticity of the light emitting chip 120 for obtaining data values of the graph shown in FIG. 4, the graph moves to the right side of the graph shown in FIG. When the chromaticity of is lower than the chromaticity of the light emitting chip 120 for obtaining data values of the graph shown in FIG. 4 , it may move to the left side of the graph shown in FIG. 4 .

Therefore, it is possible to adjust various chromaticities by varying at least one of the concentration of the dye, the thickness of the dye layer 141, and the chromaticity of the light emitting chip 120 as described above.

FIG. 5 is a graph showing radiant luminance of the night vision lighting system according to the temperature of the dye of the filter unit of the light emitting diode for the night vision lighting system shown in FIG. 1 .

와

는 각각 Class A와 Class B 장치의 상대 야시조명계통용 발광 다이오드 응답 특성을 나타내며,

은 발광칩(120)의 분광 복사휘도(Spectral radiance)를 의미하며 단위는

이며, S는 환산계수(Scaling factor)이다. Referring to FIG. 5 , in order to apply the light emitting diode 100 for the night vision lighting system to military avionics, the aforementioned chromaticity and radiant luminance of the light emitting diode for the night vision lighting system must be simultaneously satisfied. In the specified luminance of the MIL-STD-3009 standard, the radiant luminance (NR) of the light emitting diode for the night vision system is defined as in [Equation 2]. For Green A, the specified luminance is 0.1 fL (Footlamberts). In [Equation 2]

and

Represents the relative response characteristics of light emitting diodes for night vision lighting systems of Class A and Class B devices, respectively,

means the spectral radiance of the light emitting chip 120, and the unit is

, and S is the scaling factor.

The radiant luminance (NR) value of the light emitting diode for the night vision system calculated using [Equation 2] from the measured spectral radiance (NR) of the light emitting chip according to the concentration of the dye is shown in FIG. 7, and the dotted line indicates the Green A chromaticity indicates 1.7E-10, which is the basic radiant luminance (NR) value of light emitting diodes for night vision lighting systems that must be satisfied. The combination of the package body 110, which is a black body, and the filter unit 140 including a dye having a concentration of 1 wt% or more can sufficiently satisfy the requirements for radiant luminance of light emitting diodes for night vision lighting systems according to MIL-STD-3009.

6 is a cross-sectional view showing a light emitting diode for a night vision lighting system according to another embodiment of the present invention.

Referring to FIG. 6 , the light emitting diode 100 for a night vision lighting system may include a package body 110, a light emitting chip 120, a packing part 130, and a filter part 140. In this case, the light emitting chip 120, the packing unit 130, and the filter unit 140 may be the same as or similar to those described in FIG. 1 .

The package body 110 may include a package body base 111 and a protrusion 112 . At this time, the package body base 111 and the protrusion 112 are integrally formed, and both may be formed as a black body.

The protruding portion 112 may be disposed to protrude from an entrance of the opening area 110a of the package body base 111 . At this time, the protrusion 112 may be disposed to surround the rim of the filter unit 140 . In particular, when light emitted from the light emitting chip 120 is emitted to the outside through the packing part 130 and the filter part 140, the protrusion part 112 is emitted to the side of the filter part 140 due to refraction or reflection. can In this case, interference due to light leaking from the night vision system, and the inability to see a new person may occur. In this case, the protruding part 112 may block light leaking out to the side of the filter part 140 .

Accordingly, the light emitting diode 100 for the night vision lighting system can effectively provide light having a specific wavelength reduced or blocked to the front of the filter unit 140 . In particular, the light emitting diode 100 for the night vision lighting system can provide light capable of improving the performance of the night vision lighting system used at night in the field of avionics.

As such, the present invention has been described with reference to one embodiment shown in the drawings, but this is merely exemplary, and those skilled in the art will understand that various modifications and variations of the embodiment are possible therefrom. Therefore, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims.

100: light emitting diode for night vision lighting system
110: package body
120: light emitting chip
130: packing unit
140: filter unit

Claims (8)

A package body that is a black body formed by mixing black dye with resin;
a light emitting chip seated on an opening of the package body;
a filter unit coupled to the package body and blocking or reducing at least some wavelengths of light emitted from the light emitting chip; and
A light emitting diode for a night vision system including a packing part disposed in an opening area of the package body and including a resin having YAG (Yttrium Aluminum Garnet), which is a yellow phosphor,
The light emitting chip is a GaN-based blue chip,
The color temperature reaching the filter unit through the packing unit is 6500 to 7500K,
The color temperature reaching the filter unit is obtained by adjusting the concentration of YAG, which is the yellow phosphor,
The filter part,
a dye layer disposed to face the light emitting chip and mixing acrylic resin with Night Vision Imaging System (NVIS) Green A dye at a concentration of 1 wt %; and
And a protective layer disposed on the dye layer,
The filter unit blocks light having a wavelength within a range of 600 nm or more and 900 nm or less,
The chromaticity of the light emitting diode for the night vision lighting system satisfies Green A specified in MIL-STD-3009,
The chromaticity of the light emitting diode for the night vision lighting system is satisfied by the thickness of the filter unit,
The protective layer is provided with a polyethylene terephthalate (PET) film,
The dye layer is coated on the protective layer, a light emitting diode for a night vision lighting system. delete delete According to claim 1,
The package body,
a package body base having the opening area; and
and a protruding portion protruding from the package body base and disposed to surround an edge of the filter unit. delete delete delete delete

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